A very simplified wireless telecommunications system 1 is illustrated in FIG. 1 of the accompanying drawings. A user device 3 is operable to communicate in a wireless manner with an access point 5, via an air interface 7. It will be readily appreciated that the apparatus illustrated in FIG. 1 is merely intended to explain the operation of a wireless system, and should not be construed as limiting. In particular, the mobile user device 3 and the access point 5 may be provided by any suitable means known to those skilled in the art, and should not be limited to the apparatus illustrated in FIG. 1 of the accompanying drawings.
In an uplink, from the mobile user device 3 to the access point 5, transmission is performed by the user device 3 using either a contention-based channel or a scheduled channel. In contention-based transmission, the access point 5 transmits scheduling information (physical channels etc) to the user device 3 on a shared physical channel. In scheduled-based transmission, the access point 5 transmits scheduling information to the user device 3 on a dedicated channel. The key point is that the access point 5 controls the scheduling of data packets in the uplink.
Wireless systems that require high spectrum efficiency preferably need to allow reuse of channels in adjacent cells or groups of cells. For example, a so-called “1-reuse” system is one where each cell is able to use the full range of channels. A “3-reuse” system groups 3 cells together for channel allocation purposes. Consequently, different user devices 3 in adjacent cells may use the same uplink sub-carrier/chunk frequencies in such systems.
When the user device 3 transmits at high power in a cell and/or is close to a neighbouring cell, it is likely that transmission from the user device 3 will cause excessive interference in the neighbouring cell. This can lead to bad uplink macro-diversity performance. This is clearly undesirable because it leads to degraded overall performance and/or reduced capacity.
The issue of uplink inter-cell interference is well known and several solutions have been proposed. Known “radio resource management (RRM)” techniques include:                Dynamic Channel Allocation (DCA)        Fractional Load (FL)        Load Balancing (LB)        
Dynamic channel allocation is powerful technique to reduce both intra-cell and inter-cell interference. Existing DCA techniques do not consider long-term management of interferers. That is, existing DCA techniques mitigate the interference problem by assigning/re-assigning sub-carrier frequencies to user devices on a short time scale in such a manner that the interference level is kept at close-to-optimum values. The important aspect is that the “optimum” is typically defined assuming the given user device and traffic distribution in the area which is in the scope of the DCA technique. That is, it is out of the scope of existing DCA techniques to:                Take into consideration of longer term interference events, for instance the repeated occurrence of high interference on certain sub-carrier frequencies.        Perform actions taking place by virtue of the interaction between different Radio Access Nodes that aim to balance the load among adjacent cells such that the root cause of the interference is mitigated.        
Fractional Load is a well-known technique to reduce inter-cell interference. Typically, FL refers to the technique of using only a subset of the available sub-carriers in each cell and thereby reducing the probability of different user devices using the same sub-carriers. In fact, FL creates a greater-than-one reuse system, which renders it non-applicable in evolved UTRA networks.
Evolved UTRA networks can also be known as Super 3G (S3G) networks. The 3rd Generation Partnership Program (3GPP) currently standardising future wireless network techniques.
Load Balancing is a well-documented RRM technique. The basic idea is to distribute the load among cells and sectors of a cellular system in such a manner that multi-cell/sector resources are highly utilized. LB is inherently connected to the definition of load, since it creates the basis of the actual algorithm that attempts to distribute load in the system. For instance, LB can re-assign user devices by enforcing handovers such that parts of the incoming uplink traffic in highly loaded cells are “taken over” by less loaded cells. In these solutions, the LB triggering event is typically some measurement that characterizes load (incoming bit-rate, used sub-carriers or other radio resources) rather than the frequency occurrence of undesired events such as high measured interference levels of other short-term events.
Such known techniques are described in the following papers:    I Katzela and M Naghshineh, “Channel Assignments Schemes for Cellular Mobile Telecommunications Systems: A Comprehensive Survey”, IEEE Personal Communications, pp. 10-31, June 1996    Y J Zhang and K Ben Latalef, “Multi-user Adaptive subcarrier-and-Bit Allocation With Adaptive Cell Selection for OFDM Networks”, IEEE Trans. Wireless Comm., Vol 3, No. 5, pp 1556-1575, September 2004    Y J Zhang and K Ben Latalef, “Adpative Resource Allocation and Scheduling for Multi-user Packet-based OFDM Networks”, IEEE International Conference on Communications (ICC) 2004    S Das, H Viswanathan, G Rittenhouse, “Dynamic Load Balancing Through Coordinated Scheduling in Packet Data Systems”, IEEE Infocom 2003    A Sang, X Wang, M Madihian, R D Gitlin, “A Load Aware Handoff and Cell-site Selection Scheme in Multi-cell Packet Data Systems”, IEEE Globecom 2004    A Sang, X Wang, M Madihian, R D Gitlin, “Coordinated Load Balancing, Handoff/Cell-site Selection and Scheduling in Multi-cell Packet Data Systems”, ACM Mobicom 2004
In summary, existing techniques do not provide solutions that:                Provide immediate solution/reduction of interference when interference levels on certain sub-carriers get high (short time scale problem)        Take anticipatory actions, based on the short time scale events, to prevent such undesired events occur        Avoid long-term actions that are not necessary/desired. This is important, because unnecessary load balancing actions, for example increase the probability of unnecessary handovers, may increase transport network load and may even cause undesired “ping-pong”-ing effects.        Ensure coordinated interaction between different radio access nodes such as the access point and a central controller to control uplink interference.        